THRIFT-870. java: Java constants don't get Javadoc comments

Fix a trivial oversight.

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@996592 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/test/DebugProtoTest.thrift b/test/DebugProtoTest.thrift
index d4c8759..b01129a 100644
--- a/test/DebugProtoTest.thrift
+++ b/test/DebugProtoTest.thrift
@@ -272,6 +272,7 @@
   TWO = 2
 }
 
+/** This is a docstring on a constant! */
 const SomeEnum MY_SOME_ENUM = SomeEnum.ONE
 
 const SomeEnum MY_SOME_ENUM_1 = 1